1. Field of the Invention
The invention relates to an interconnector for high temperature fuel cells and to a fuel cell battery.
2. Description of the Prior Art
The fuel cells of a fuel cell battery in accordance with the invention comprise (see EP-A 0 714 147) in each case a so-called PEN and an interconnector which connects the cells adjacent to the PEN in an electrically conducting manner and at the same time separates a combustion gas (in particular a mixture of carbon monoxide and hydrogen) from a gaseous oxygen carrier (in particular air). The PEN has a planar three-layer construction consisting namely of a solid electrolyte (E), a positive electrode (P) and a negative electrode (N). Electrochemical reactions at the PEN with the fuel and the oxygen of the oxygen carrier take place at about 900.degree. C.
Due to the high operating temperatures, a material must be used for the interconnectors of which the coefficient of thermal expansion is largely equal to that of the solid electrolyte. A powder-metallurgically manufactured alloy is known which is suitable for the manufacture of interconnectors. This material, which consists mainly of chromium (about 95% by weight) and which is manufactured through sintering at high pressure and high temperature, is expensive. The alloy is manufactured in plate form and must therefore be further processed in a form suited to the function of the interconnectors, with complicated and expensive work steps being required and material being lost.